During the overhaul or rebuilding of a liquid cooled internal combustion engine, or during the manufacture of such engines from the used parts of several engines, a preferred step is to test for leaks in the head or manifold of such engines before their assembly into the rebuilt engine. The equipment offered today from established manufacturers is considered to be of high cost and also to require excessive set up times. A review of U.S.A. patents has not presented such test equipment which could be manufactured for substantially less cost, nor which could be used more conveniently, especially in reference to shorter set up times. However, the review of these patents did disclose the following:
In 1968, Messrs. Salsbury, Fegel, and Larson, in their U.S. Pat. No. 3,360,984, illustrated and described their universal engine cylinder head testing apparatus. A cylinder head was supported on four adjustable height columns with the fire deck surface of the head facing upward. Spaced away on each side of the head were rails. Along the rails individual sealing units were adjustable longtitudinally and transversely to respectively seal each respective opening in the fire deck surface of the head to be tested. During the test the head was held in the same position. Considerable time was involved in placing the head on the four columns, and in placing the seals over the openings in the fire deck surface;
In 1971, Mr. Herbert O. Wilkinson in his U.S. Pat. No. 3,608,369 illustrated and disclosed his engine head test stand, which pivotally supported the engine head after it was clamped in position. During the clamping, selections were made from different clamping units, and selections were made from different engine support plates;
In 1973, Mr. Charles K. Crawford, in his U.S. Pat. No. 3,751,978 disclosed his vehicle motor block tester and method of using the same. Although an engine block rather than an engine head was tested, he did show how a test stand could be pivoted in a limited way. Also he indicated that continuous seals, preformed for certain types of engines, could be placed down on a motor block. Then the seal is covered with a preformed plate, and the seal in turn is covered with a hold down unit having spaced apart cables or clamps;
In 1976, Mr. Virgil R. C. Durgan in his U.S. Pat. No. 3,973,429 illustrated and described his test apparatus for engine heads. At the outset, an engine head with its fire deck below is clamped to a pivotal frame. Thereafter, the pivotal frame is pivoted to place the fire deck above. Then using side rails different selected individual sealing units are placed over respective openings on the fire deck, and thereafter various tests are undertaken inclusive of using hot water under pressure to find any possible leaks in the engine head;
In 1979, Mr. George A. Moffet III in his U.S. Pat. No. 4,157,028 disclosed his portable universal apparatus for use in pressure testing engine cylinder heads and blocks. They were clamped with the fire deck above, between lower spaced transverse bars supported as a group at bench level and overhead transverse bars using bolt and nut fasteners extending between the lower and overhead transverse bars. On each side of the fire deck a continuous strip seal with a respective backing plate was included during the overall clamping to seal the entrances to the coolant passageways. Thereafter these passageways were filled with compressed air, and then the entire apparatus with the head in place was submerged in a hot water vat to check for leaks by possibly observing the formation of escaping air bubbles; and
In 1980, Ronald C. Roeschlaub in his U.S. Pat. No. 4,213,328 illustrated and described his apparatus for fluid pressure testing of engine cylinder heads and similar parts. A lockable pivotal frame positioned an engine cylinder head which was clamped into place utilizing longitudinal members on each side, transverse members and vertical hold down bolt and nut fasteners. These fasteners also positioned individual seals for nearby fluid openings, and at other places individual sealing units were especially held in place by special fasteners.
Although collectively the disclosure of these patents describe the pressurized fluid testing of engine cylinder heads and engine blocks to determine if there are any leaks, and in so doing these patents also disclose pivotal mountings of test stand components, so an engine part under test may be rotated during possible leak observations. Moreover, these patents show the use of separate continuous gasket seals to be placed over openings to the coolant cavities and/or passageways in the engine part under test, and in so doing disclose adjustable hold down subassemblies to position the engine parts. Yet, as indicated by the available test stands offered in the marketplace, there remained a need for a lower cost portable engine cylinder head test stand, which could quickly and sealably receive an engine cylinder head for pressurized hot water testing, and be rotatable for the inspection of leaks throughout all the exterior surfaces, except for the surface of the fire deck of the cylinder head.